In the conventional Kraft process, wood pulp is produced by digestion of wood chips in a pulping liquor usually containing sodium hydroxide and sodium sulfide as the active pulping chemicals. Following the wood digestion process, pulp is separated from the spent pulping liquor. The spent pulping liquor is then recovered and regenerated for recycling. The Kraft process wood pulp is then bleached and purified in a bleach plant operation. In the bleach plant, pulp is usually subjected to at least one bleaching stage under acidic conditions with a bleaching agent such as ozone, chlorine, chlorine dioxide, mixtures of chlorine and chlorine dioxide and the like, followed by at least one bleaching stage under alkaline conditions with a bleaching agent such as hydrogen peroxide, oxygen or a combination thereof. Depending on the desired pulp brightness, additional acidic or alkaline bleaching stages are employed. Following each bleaching stage, spent bleaching chemicals are usually removed from the pulp by washing with a suitable source of water; as for example fresh water or previously used water from pulp washing or a combination of the two.